Georg kalischer



many, Runner ltlliinman. a citizen of Patented Dec. 8, 1925.

UNITED STATES PATENT QFFECE.

G-EORG KALISCHER, OF MAINKUR, NEAR FRANKFOET-ON-THEJEAIN, AND RUDOLF M'U'LLER AND FRITZ FRISTER, 01'" FECHENHEIM, NEAR FRANKFURT-ON-THE- MAIN, GERMANY, ASSIGNORS TO LEOPQLD CASSELLA 80 CO. GESELLSCI-IAFT MIT BESCHRANKTER HAFTUNG, A CORPORATION OF GERMANY.

PROCESS FOR THE FRODUCTION OF BENZANTHRONE DERIVATIVES.

No Drawing.

To all 'lU/(O'flt it may concern.

Be it known that we, Gnome Kamsonnn, a citizen of the German Republic, residing at Mainkur. near Fltllll l ()It Oll-tllQ-hltlill, Gerthe German Republic, residing at l echcnheiin, near Franktort-on-the-hlain, Germany, and Fnrrz Fms'rnn, a citizen of the German Republic. residing at l echenhcim, near Frankfort on-the-hflain, Germany, have invented a Process for the Production of Benzanthrone Derivatives, of which the following is a full description.

\Ve have found that; benzanthrone derivatives may be obtained according to a new The a-naphthalene-azo-m carboxylic acid or its substitution products serving as starting materials for the new process may be ob tained by boiling with alcohol the diazoeoinpounds of the azo dyes, which are formed by combining diazobenzenean-carboxylic acid with a-naphthylai'nine or its derivatives. Generally speaking only those derivatives of oz-naphthalene-azo-benzene-m-carboxylic acid can be used for the new process, in which the ana-5-position corresponding to the azo group of the naphthalene nucleus and the two p-positions to the axe-group (the C- atoms marked in the first formula by a+) are not substituted.

The reduction of the azocompounds may be effected with all the reducing agents used hitherto for this reaction, i. e. stannouschloride. sulfurous acid, Zinc dust etc. The reduct-ion and the transformation of the hydra- Serial No. 16,795.

process entirely different from any one used hitherto and which consists 1n reducing z- .napthalenc-azo-ben zene-m-carboxylic acid or the substitution products thereof to the hydrazo coinpounds, in transforming the otnaphthalene hyd 'azo-benzcue-ln-ca-rbo ;yl ic acids thus obtained in acid solution into the t-t diaminonaphthylphenyl 2 carboxylic acids and in condensing the latter by means of acid condensing agents to benzanthrone derivatives. The differentphases of the reaction may be represented by the following formulae. oz-naphthalene-az0-benzenem-carboxylic acid being used as prototype for the whole class:

yn2 bllHg to coon 11 ,1 2t

NH; tire A suspension of 48 kg. of the sodium salt of the oz-naphthalene-aIce-henzene-m-earboxylic acid in 200 kg. alcohol is allowed to run within hour at 50 into a solution of Cit 112 kg. stannous chloride in 360 kg. concentrated hydrochloric acid, the temperature being kept below 60. In order to ensure complete transformation, the solution is stirred for some time at 50 and the reaction product is then separated by filtration. For purifying the dihydrochloride oi the etxl -diaminonaphthylphenyl2 carboxylic acid thus obtained, the raw product is dissolved in hot water and separated again as a light grey sediment by the addition of concentrated hydrochloric acid. By addi tion of the calculated amount of alkali, the free diaminonaphthylphenylcarboxylic acid, which is sparingly soluble in water, is precipitated, whereas with an excess of alkali the easily soluble sodium salt is formed. By the action of nitrous acid an easily soluble golden yellow tetrazocompound is obtained, which yields with R-salt a violet dyestufi'.

The o-naphthalene-aZo-benzol-mcarbi xylic acid required for the process may be obtained by boiling the diazo compound of the dyestufi' from m diazobenzoic acid and naphthylan'iiue with alcohol.

The a-naphthalene-aZo-bcnzolun-carboxylic acid crystallizes from glacial acetic acid in yellow-brown needles of F. P. 207 and yields a sodium salt sparingly soluble in hot Water.

Erma 17c 2.--D iam-inolmnew 7% r no.

it! kg. of the hydrodi-cliloride obtained according to ll lxai'nple l are gradually added to lill kg. oi chlorosnll onic acid at a. temperature not exceeding 10'. The condensation commences at once and is complete after stirring for 1 hour at 10". 'lllre htpilllliilill oi the diaininobenzanlhrone is el'l'ecled by alloi'ving tho reactioi'ionixtrire to How on an excess of ice and transforming the separating s iaringly soluble sullate into the free base by the addition of alkali. The dianiinol'ienzanthrone thus obtained. of the torniula is a dark violet powder which is insoluble in water and is forming with sulfuric acid in aqueous solution a diiticultly soluble sulfate. It dissolves in organic solvents with a violet color, and has it rte-crystallized from these solvents a melting point of about 22:3" C. .l i ith concentrated sulfuric acid a yellow brown green-fluorescent solution is formed. By means of nitrous acid a tetrazo body is obtained soluble in water with a brownish yellow color and yielding with lit-salt a blue disazo dyestui'l".

Into a suspension of kg. of finely ground a-naphthalene-azo 2 inethylbenzolni-carboxylic acid of the itormula:

GOOH (II Ia to which a solution of 0.2 kg. potassium iodide, in 90 kg. concentrated hydrocl'iloric aci d has been added, sulturous acid is introduced in a slow current at a temperature of 2530, while stirring continually, until the axe com i ound has disappeared and the transformation is complete which is the case after 5-6 hours.

The precipitated sulfate oi the ta -diainino naphthyl-S anothylbenzol-Q carbonylic acid is separated as indicated in Example 1 and shows properties very similar to the compound described therein. The reduction and transliorn'iation may likewise be eltected in a closed vessel by passing the sulturoiu-i acid into the reaction-niixtnre.

'lhe Ofi-llttPllilltllOliO-tlZfi-lllttllyllitllIdUl--lllcarboaylic acid en'iployed in this example is oliilained from the azo dyestul'l' 't'roin diazotised ainino l-niethlyhenzol-lwarbmrylic acid and e-naphthylaniino; arlt'tei' rc-cl'ystab lizing 't'roni glacial acetic acid it is obtainial in the form of browwyellow crystals of F. l. 2236.

it) he. ol the sulfate obtained according to Example 3 are gradually added to .150 kg. i'i'ionohydrate in order to prevent the temperature from rising above After stirring for 1 hour, the whole is poured on ice, and rendered alkaline with caustic soda solution. The diaminomethylbenzanthron'e of the formula:

llll) which has separated in the form of blue flakes is filtered oil. For purifying the same it is lQ-PlQClPi'EELtQCl from a solution in dilute hydrochloric acid, and then if necessary recrystallized from solvents of a high boiling point. The diaminomethylbenzanthrone has exactly the same properties as its lower homologue obtained according to Example 2. The condensation to the bezanthrone derivative is also easily effected by heating with other condensing agents, for instance with zinc chloride at 120. Condensation may also be combined with reduction and transformation in one operation, by adding the necessary quantity of alun'iinium bronze to the solution of the azo body in concentrated sulfuric acid.

The axe-compound of the formula O C H:

obtained from the monoazo dyestutl' of m-diazobenzoic acid and 1amino-7-inethoxynaphthalene, by elimination of the amino groups, is converted into the -l.-l -diamino-7- metlioxynaphtl1yl-phenyl-T-carboxylic acid of the 't'ormula:

OCIls This compound has nearly the same properties as the product obtained according to Example 2. Its solution in glacial acetic acid, pyridine and the like is dyed blood-red. The solution in concentrated sulfuric acid is green-yellow with a strong green fluorescence. By means of nitrous acid a brown colored tetrazo body is obtained yielding with Rsalt a blue disazo dyestutl'.

in exactly the same manner a benzanthrone derivative is obtained from the monoazo dyestutl' from m-diazobenzoic acid and 1- anlino-T-chlei-naphthalene, ot' the constitution which dissolves in concentrated sulfuric acid with an orange shade, slightly fluorescent, and in organic solvents as for instance aniline, with a magenta-red color, and forming by tetrazotizing in the usual manner a brownish olive colored tetrazo compound yielding with R-salt a blue disazo dyestutl.

Having now particularly described and as certaincd the nature of our said invention and in what manner the same is to be performed, we declare that what we claimis 1. Process for the production of benzanthrone derivatives which consists in treat ing oc-naphthalene-azobenzene-m-carboxylic acids (in which the C-atoms 4, 5, and 4 corresponding to the following "formula:

are not substituted) with reducing agents in an acid solution, and condensing the diaminonaphthylphenyl-o-carboxylic acids thus obtained and represented by the following general formula:

The C-atoms 2, 3, 5, G, 7, 3 5 6 may be substituted by univalent groups (as CH halogenes, O-Alkyl) with acid condensing agents substantially as described.

2. Process for the production of diaminobenzanthrone which consistsin treating anaphthalene-azo-benzene-m-carboxylic acid with reducing agents in an acid solution and condensing the diaminonaphthylphenyl-ocarboxylic acid thus obtained and represent ed by the following formula:

| I Y i C OOH- with acid condensing agents substantially as described.

As new articles of manufacture the al.4 diannnobenzanthrones produced. aceordlng to claim 1 of the following formula:

/ 5 4 ,6 3 7 g A 1 i The C-atoms 2, 3, 5, 6, 7, 3 5 6 may I be substituted by univalont groups (as 011 Halogcncs, Oddkyl) O U 2 G i i NHg these 4A dialnino benzanthrone derivatives being dark violet powders soluble in organic solvents, yielding with concentrated sulfuric acid yellow to brown solutions with a sig niticant fluorescence forming with sulfuric acid in aqueous solution rather diflicultly soluble salts, and the terrazo bodies thereof being soluble in water with a yellow to brown color and yielding with ltsalt Violet to blue disazo dyestufis.

4t. As new article of manufacture the 4.4 dianiino benzanthrone prepared according to claim 2 of the following formula GEORG- KALISCHER. RUDOLF MULLER. FRITZ lFRISTER. 

